It's a figure that's almost mind-boggling. Kronos Quartet, the American string quartet that redefined what a string quartet could play and work with, have commissioned more than 800 original compositions in the past 40 years. That's 20 a year.
On top of that, the quartet have worked with a broad number of artists across music genres, including David Bowie, Nelly Furtado, Philip Glass, Nine Inch Nails and Joan Armatrading.
But for violinist David Harrington, who founded the quartet in September 1973, there's one composition that sticks out.
It's the work Arum Manis, written by Wellington composer Jack Body for the quartet in 1991. They will revisit Body's piece when they perform in Wellington on Monday.
"I had always wanted Kronos to be able to play music from many different places in the world and the very first time we came to New Zealand was when Jack Body wrote for us. One was from the music of China, one from Madagascar and another from Bulgaria. Those three arrangements that he did really opened up an entire panorama of possibilities," says Harrington.
"That's not to say that we hadn't been trying to do things before that had resonances with various cultures. But here in one piece we had this kind of global vision. I really think that that piece is a very important part of our work. I'm not just saying that because I'm talking to you from New Zealand. I'm saying it because I think Jack's piece really needs to be credited for what it has done for music."
The same could be said for Kronos itself. Since the quartet last played Wellington in 2005, they have continued to record - 45 albums and counting - and tour for several months each year.
They've also concentrated more on mentoring other string quartets, including workshops at Carnegie Hall in 2007, and commissioning works including young composers with its Under 30 Project.
Harrington says having compositions in the hundreds is in stark comparison to 40 years ago when he was inspired to found the quartet after hearing composer George Crumb's experimental Black Angels.
The work, a comment on the Vietnam War, included spoken word, electronic effects and bowed water glasses. To this day, pre-recorded tapes and amplification are as much a part of the quartet's sound as violin (Harrington and John Sherba), viola (Hank Dutt) and cello (Jeffrey Zeigler).
"Right at the beginning in 1973 most composers had given up on the idea of the string quartet. I think too many of them listened to [French composer Pierre] Boulez. He famously said the form was dead. But what he didn't take into account was that George Crumb had written Black Angels in 1970 and I just happened to hear that. It changed my life.
"That piece gave me hope and it gave me a voice. I was a young person in American society who had grown up during Vietnam and I was trying to work out what to do with myself and how to express some of the complex feelings that I had about that war and the world I had inherited. All of a sudden, that piece gave me some musical answers. I don't think Boulez counted on that."
The diversity of Kronos' approach will be heard throughout its Wellington concert, including Serbian composer Aleksandra Vrebalov's . . .hold me, neighbor, in this storm. . . Harrington says every commissioned work, like Vrebalov's, has a special history.
This piece started when he got a call from Vrebalov in 1995 when she was a music student in San Francisco. "She said, ‘I have a string quartet piece that I would love you to look at. Can I drop it off?' I said, ‘Certainly'. She came over to our office and had a cup of coffee and basically we've been friends ever since."
Hold me, neighbor is her fourth Kronos commission. It was inspired by Harrington seeing an "amazing" documentary about the close-knit Serbian community in Chicago.
He played it to Vrebalov and told her he couldn't understand what was happening in Serbia at that time.Could she write a piece of music that could explain it?
Harrington says the result brought together many different aspects of Serbian culture and he had to learn to play - "by watching YouTube videos" - the gusle, a Balkan single string instrument. The piece also includes recorded sounds of bombs dropping during the Yugoslav wars.
"This piece really takes the listener to places that most of us haven't been to. Through her work we experience some of the elements of Serbian culture. I think it is amazing music."
That topical resonance is also in another work in the concert, WTC 9/11, on the World Trade Center attack, by top contemporary composer Steve Reich.
For Harrington there's an embarrassment of riches in what the quartet can play after 40 years.
"The music that is being written for Kronos now is definitely a result of all the other music that has been written. The people that we work with, many of them are aware of the other work that we've done. Things kind of accumulate.
"I think the thrust of the various directions we've taken has really shown results and I'm really pleased with this. I don't think there's any other way to have this kind of feeling that I have right now. To me, the work is getting more thrilling, more exciting and I'm more on the edge of my chair than I've ever been before in all of these years.
"It's not work. It might seem like it to someone on the outside. Last night is a good example. After a concert with Laurie Anderson she and I were talking about what it means to be a musician in this time and our responsibility. I get to have conversations like that every day with incredible people."
Kronos Quartet play
March 9, The Civic, Auckland
March 11, Michael Fowler Centre, Wellington
March 13, Regent Theatre, Dunedin
March 14, Aurora Centre for the Performing Arts, Christchurch
- The Dominion Post